1. Field of the Invention
This invention relates to a tensioner for an endless power transmission belt or the like as well as to a method for making such a tensioner.
2. Prior Art Statement
It is known to applicants to provide a tensioner for a power transmission belt that is adapted to be operated in an endless path, the tensioner comprising a support means for being fixed relative to the belt, a belt engaging means carried by the support means and being movable relative thereto, mechanical spring means operatively associated with support means and the belt engaging means for urging the belt engaging means relative to the support means and against the belt with a force to tension the belt, and fluid dampening means operatively associated with the support means and the belt engaging means to dampen the movement of the belt engaging means relative to the support means, the dampening means comprising a piston means and cylinder means having the piston means and a fluid therein. The piston means defining two chambers for the fluid in the cylinder means on opposite sides of the piston means and having a piston rod interconnected to one of the opposed sides thereof and extending through one of the two chambers, the piston means and cylinder means having means that fluidly interconnects the two chambers together in a restrictive manner to provide a dampening effect upon relative movement between the piston means and the cylinder means upon the movement of the belt engaging means relative to the support means.
For example, see the co-pending patent application Ser. No. 296,694, filed Aug. 27, 1981 of Leslie B. Wilson, one of the applicants of this application.
It is also known in the art to provide a piston and cylinder arrangement for hydraulically urging an idler pulley in tensioning engagement against a belt.
For example, see the following two United States Patents:
(2) U.S. Pat. No. 3,142,193--Polko et al
(3) U.S. Pat. No. 4,276,038--Kraft